The discovery of high Tc-superconductors was one of the most important discoveries during the last years. There was a lot of work done since this time (1986, Bednorz and Mueller) in order to obtain a better understanding of this new materials. But still it is not possible to describe the behavior of the high-T_c-superconductors on a microscopic level.
In my talk I want to introduce a model that describes magnetotransport of cuprates in the normal state (NS). There is experimental evidence (ARPES) that it is sensible to use the Boltzmann-equation (BE) for the description of transport phenomena in this state (quasiparticles with finite lifetime!). A very simple model for the scattering mechanism in the CuO2-layers is introduced. This model helps us to solve the BE in a perturbation expansion in the magnetic field.
In particular two regions, cold and hot regions, are introduced to describe the scattering on a phenomenological level. As we are interested in the temperature dependence on DC-transport data we give the scattering in the different regions different temperature dependences. Our goal is to describe a model that gives good agreement with the data we obtain from experiments for DC-Resistivity, Thermoelectric Power, Hall-angle, Magnetoresistance and thermal Hall-angle this approach. The idea of cold spots and hot spots gives good agreement with the experimental data, at least in the case of magnetotransport.
The talk will explain the "two-patch-model" in an easy way. The symmetry of this model allows us to derive electrical and magnetical conductivities from the BE. We compute transport properties in a numerical way and compare them with experimental data. The agreement is pretty good. At the end we might discuss the problem of fitting the data (there are 5 parameters in the model) and the question of Fermi-liquid-corrections.
As the model and the calculations are quite easy to understand I think everybody can understand the basic ideas of the talk.
See you in the seminar!